Air delivery apparatus for fuel combustion



Ap 3, 1934. H. MEACHEM AIR DELIVERY APPARATUS FOR FUEL COMBUSTIONOriginal Filed 1951 S'SheetS-Sheet l INVENTOR fizryjyzarfizm/ BYATTORNEY April 3, 1934. H. MEACHEM 1,953,757

ua DELIVERY APPARATUS FOR FUEL comauswzon Original Filed Feb. 25. 1931 3Sheets-Sheet 2 INVENTOR filrry flfmcirem ATTORNEY April 3, 1934- H.MEACHEM 1,953,767

AIR DELIVERY APPARATUS FOR FUEL COMBUSTION Original Filed Fe 25. 1951 sSheets-Sheet s INVENTOR Harry Hear/um ATTORNEY Patented Apr. 3, 1934UNITED STATES PATENT OFFICE AIR DELIVERY APPARATUS FOR FUEL COMBUSTIONHarry Meachem, Teaneck, N. J., assignor to Todd Dry Dock, Engineering &Repair Corporation,

Brooklyn, N. Y.

1 Claim. (Cl. 15877) This application, which is a division of myapplication Serial No. 518,138, filed February 25, 1931, relates toapparatus intended for the delivery to burners of air supplies, bothprimary and secondary, for the efficient combustion of uel.

My investigations in fuel combustion have led me to believe that bycausing the fuel to issue whirlingly into the combustion zone, and pro-0 viding a concentric envelope of primary air flowing in contactingrelation with the fuel, whirling in the same direction, and joining thefuel at the root of the flame, a condition is set up whereby the fueland air, spinning at high rotative velocity, are induced to intermingleand blend into a more perfect mixture than has been availab by any ofthe methods in vogue.

This method of associating the fuel and primary air results in theproduction of a relatively short, bushy, flame, whose propagationproceeds whirlingly through an unusually prolonged rotative path, inwhich the fuel continues to burn in suspension with great efficiency.

The secondary air employed by me is caused to whirl in the samedirection of rotation as the primary air and fuel, and is drawn into theflame over a deflector, thereby providing a large volume of air thatenvelopes the flame and supplies the necessary amount of oxygen toeffect complete combustion. The flow of the secondary air is inundivided volume, by which is meant that it enters the furnace throat ina volutely moving mass, instead of being divided into streams by the useof vanes, as has previously been resorted to, and therefore thesecondary .air is enabled to blend in with the other constituents of theflame.

Other features and advantages of my invention will hereinafter appear.

In the drawings:

Figure 1 is a face view of my improved fuel burning apparatus. v

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a section on the line 3-3 of Fig. 2, and

Fig. 4 is a section through the flame cone on the line 4-4 of Fig. 2.

In the drawings 1 indicates the usual Venturi ring, which is enteredthrough an opening provided therefor in a furnace front plate 2, saidring 1 being connected with a box-like structure, through which air issupplied to the furnace for combustion purposes. This supply of air istermed the secondary air, and the air box is so constructed that it willcause the air flowing 'therethrough, under either natural or forceddraught, to enter the furnace whirlingly through ring 1, in a volute,undivided volume.

To this end the air box has a partly spiral peripheral wall 3 that, withthe ring 1, contains the fuel atomizer and primary air supply means. v30But, whilst the burner and primary air supply means (which will both bedescribed hereinafter) are centered within the ring'l, they are disposedeccentrically with respect to wall 3, being nearer that portion of thewall whence the flowing air 5 passes into ring 1 than to the portion ofthe wall where air has its entry into the air box.

The air box is bounded by a forward plate 4 and a back plate 5, exceptthat a circular clearance in back plate 5 registers with the larger di-7 ameter of ring 1.

The partly spiral form of wall 3 continues from a vertical wall portion6, which latter, with the forward and. rearward plates 4, 5, and a base"I, provide between them an air inlet 8, that is con- 7 trolled by adamper 9, hinged at 10 near wall portion 6, and provided with a handle11 for its operation, whereby the area of the inlet opening may bevaried.

The partly spiral wall in its curvature gradu-- 3o ally restricts thearea encompassed between it and the circle represented by the largerdiameter of ring 1, meeting that circle about in a horizontal planebisecting said ring, thence continuing in said circle, as wall portion12, to a point, indicated at 13, approaching a vertical planetransversely bisecting the ring.

Said wall portion 12, plates 4 and 5 and base '7, unite to form apassageway, having inlet 14, for the inflow of additional air into theair box. The base 7 has an upwardly curved extremity 15 to aid indirecting the air stream entering inlet 14 into the course of the airstream entering the air box through inlet 8.

From the foregoing description of the air box formation, with its partlyspiral peripheral wall, within which the atomizer and primary air supplymeans are eccentrically located, and bearing in mind that the inletportion of the air box is larger in area than the furnace throat reprem0sented by the ring 1, and that the area of the air box becomescontracted toward the end of the partly spiral wall 3, then it becomesevident that the stream of air flowing to the furnace through the airbox, concentrates in its spiral path and is caused to pass through ring1 in a volute, whirling volume.

The manner in which this volume of secondary air co-acts with themixture of fuel and primary air, will be referred to hereinafter, it nowbeing no desired to describe the supply means for the fuel and theprimary air.

The atomizer employed in my improved fuel burning apparatus, andillustrated herein, forms the subject of a companion case, filedFebruary 25, 1931, with Serial No. 518,139, and only such featuresthereof will be described herein as are necessary for an understandingof the improvements comprised in this application.

Thus the atomizer has a casing 15' that contains a multiflanged spindle16 which connects with the shaft 1'? of a motor 18 whereby said spindleis driven at high speed. Liquid fuel is introduced into thecasing 15 asby means of a tube 19, which receives its supply from a branch 20 ofliquid fuel pipe line 21. The pressure under which liquid fuel isdelivered to the atomizer need be only moderate, since the high speed atwhich the spindle rotates, which may for example be 3500 R. P. M., andthe flanges on the spindle, which are spaced apart and provided withstaggered communicating notches, drive the fuel whirlingly, and at greatvelocity, through the atomizer. The spindle is provided with a head 22,having a convex inner surface that lies opposed, in spaced relation tothe outer, reamed end of casing 15, leaving a circularly inclined slit Afor the emission of fuel, which thus is caused to issue in a whirlingfilm, having a tendency ,to flare radially.

It is to correctthis latter tendency that I provide means for deliveringat the root of the flame a hollow column of primary air, whirling athigh speed in the same direction of rotation as the liquid fuel, tothereby restrict the radial area of the flame while permitting flamepropagation to be continued in an extended circular path during whichthe fuel may burn in suspension.

These primary air delivery means comprise a blower like that forming thesubject of my patent application Serial No. 484,358, filed September 25,1930, and is here represented by the casing 23, containing the impellerblades 24, driven by the motor 18. Said casing 23, which may be circularin form, communicates at its periphery with a concavo-convex passageway25 that is defined by the dished members 26, 27, which are in spacedrelation in order to provide the passageway 25. The members 26, 2'? areconnected by a series of curved membranes B that lie in the rotatingflow path of the air, to thus avoid retarding the speed of flow.

The air box plate 4 is provided with a clearence to permit theprojection of members 26, 2'7 therethrough into the air box, the member26 having a central boss 28, whose forward portion serves as a bearingfor the motor shaft 17, while its rearward portion is provided with anenlarged axial bore 29, to receive the forward portion of atomizercasing 15'. A tubular member 30 is placed concentrically about theatomizer casing 15', and has a forward enlarged portion 30 that is inscrew threaded engagement with the rearward, terminal portion of member27, said tubular member 30, with the casing 15, providing between theman annular passageway 31 that forms a continuation of passageway 25.

Passageway 31 terminates just anterior the fuel emission slit A, so thatthe supply of primary air, which is forced whirlingly by the impellerthrough passageways 25 and 31, at high speed, issues in a hollowrotating column into contact with the conoidal film of fuel that issuesmean? from slit A, the fuel and air both rotating in the same directionand assuming a partly spherical form. The flame produced with thisadmixture of fuel and air is prevented from tailing out radially by thepressure of air that issues from passageway 31 and contacts the flame atthe root thereof, because the fuel and air, both whirling in the samedirection, circle together through a rotary path of unusual extent andtime duration. Because the fuel is in suspension in the zone of maximumheat all through the period of rotative travel, thereby the process ofcombustion is enabled to be thoroughly performed.

Although the mixture of fuel and primary air, referred to, plus asuitable supply of secondary air affords excellent results, I have foundthat the addition of the secondary air by the improved supply meanshereinbefore described, namely, whereby it is caused to enter thefurnace whirlingly in undivided volute volume, rotating in the samedirection as the fuel and primary air, thereby a perfect blend iseffected between the several combustible elements, sufficient oxygen issupplied to support combustion, the speed of rotation is maintained, andthe volume of secondary air becomes an enveloping mantle to furtherrestrict the radial tailing off of the flame, tending instead to confinethe flame in a whirling bushy mass.

A flame cone, indicated at 32 as surrounding the atomizer performs itspart in the general efficiency of the apparatus, said cone providing arestricted, annular path between it and the ring 1 for the major portionof the secondary air, which thus joins the flame in its larger radius,whilst a series of angular slits 33 through the cone serve to supplysome secondary air to protect the cone from the intense heat.

The slits 33 are so angled as to maintain for the air passingtherethrough the same direction of rotation as the main volume ofsecondary air, because, as has been previously set forth, the speed ofrotation of the combustible elements must not be retarded, and theseelements, all whirling in one direction under their own impellingforces, blend perfectly in a homogeneous combustible mass.

Variations within the spirit and scope of my invention are equallycomprehended by the foregoing disclosure.

I claim:

A liquid fuel burner comprising means for spraying fuel into acombustion chamber in a whirling stream, a casing including dishedmembers arranged in spaced relation to define a passageway extendingconcentrically with said spraying means, rotatable air impeller meansmounted within said casing for delivering a hollow column of primary airby way of said passageway, about the fuel stream, a ring disposedconcentrically with said passageway and a secondary air supply boxpositioned between said ring and casing and arranged eccentrically ofsaid ring, said box having an inlet and including a partly spiral wallwhose curvature approaches the center of said ring to form aprogressively restricted continuous passage extending from said inlet inthe direction of rotation of said primary air impeller means fordelivering a volutely whirling undivided volume of secondary air toenvelop the fuel and primary air, its direction of rotation being thesame as that of the primary air.

HARRY MEACHEM.

